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-rw-r--r--src/freedv_vhf_framing.c866
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diff --git a/src/freedv_vhf_framing.c b/src/freedv_vhf_framing.c
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+/*---------------------------------------------------------------------------*\
+
+ FILE........: fsk.c
+ AUTHOR......: Brady O'Brien
+ DATE CREATED: 11 February 2016
+
+ Framer and deframer for VHF FreeDV modes 'A' and 'B'
+ Currently designed for-
+ * 40ms ota modem frames
+ * 40ms Codec2 1300 frames
+ * 52 bits of Codec2 per frame
+ * 16 bits of unique word per frame
+ * 28 'spare' bits per frame
+ * - 4 spare bits at front and end of frame (8 total) for padding
+ * - 20 'protocol' bits, either for higher layers of 'protocol' or
+ * - 18 'protocol' bits and 2 vericode sidechannel bits
+
+\*---------------------------------------------------------------------------*/
+
+/*
+ Copyright (C) 2016 David Rowe
+
+ All rights reserved.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License version 2.1, as
+ published by the Free Software Foundation. This program is
+ distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+ License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include "freedv_vhf_framing.h"
+#include "freedv_api_internal.h"
+
+/* The voice UW of the VHF type A frame */
+static const uint8_t A_uw_v[] = {0,1,1,0,0,1,1,1,
+ 1,0,1,0,1,1,0,1};
+
+/* The data UW of the VHF type A frame */
+static const uint8_t A_uw_d[] = {1,1,1,1,0,0,0,1,
+ 1,1,1,1,1,1,0,0};
+
+/* Blank VHF type A frame */
+static const uint8_t A_blank[] = {1,0,1,0,0,1,1,1, /* Padding[0:3] Proto[0:3] */
+ 1,0,1,0,0,1,1,1, /* Proto[4:11] */
+ 0,0,0,0,0,0,0,0, /* Voice[0:7] */
+ 0,0,0,0,0,0,0,0, /* Voice[8:15] */
+ 0,0,0,0,0,0,0,0, /* Voice[16:23] */
+ 0,1,1,0,0,1,1,1, /* UW[0:7] */
+ 1,0,1,0,1,1,0,1, /* UW[8:15] */
+ 0,0,0,0,0,0,0,0, /* Voice[24:31] */
+ 0,0,0,0,0,0,0,0, /* Voice[32:39] */
+ 0,0,0,0,0,0,0,0, /* Voice[40:47] */
+ 0,0,0,0,0,0,1,0, /* Voice[48:51] Proto[12:15] */
+ 0,1,1,1,0,0,1,0};/* Proto[16:19] Padding[4:7] */
+
+/* Blank VHF type AT (A for TDMA; padding bits not transmitted) frame */
+static const uint8_t AT_blank[] = { 0,1,1,1, /* Proto[0:3] */
+ 1,0,1,0,0,1,1,1, /* Proto[4:11] */
+ 0,0,0,0,0,0,0,0, /* Voice[0:7] */
+ 0,0,0,0,0,0,0,0, /* Voice[8:15] */
+ 0,0,0,0,0,0,0,0, /* Voice[16:23] */
+ 0,1,1,0,0,1,1,1, /* UW[0:7] */
+ 1,0,1,0,1,1,0,1, /* UW[8:15] */
+ 0,0,0,0,0,0,0,0, /* Voice[24:31] */
+ 0,0,0,0,0,0,0,0, /* Voice[32:39] */
+ 0,0,0,0,0,0,0,0, /* Voice[40:47] */
+ 0,0,0,0,0,0,1,0, /* Voice[48:51] Proto[12:15] */
+ 0,1,1,1 };/* Proto[16:19] */
+
+/* HF Type B voice UW */
+static const uint8_t B_uw_v[] = {0,1,1,0,0,1,1,1};
+
+/* HF Type B data UW */
+static const uint8_t B_uw_d[] = {1,1,1,1,0,0,1,0};
+
+/* Blank HF type B frame */
+static const uint8_t B_blank[] = {0,1,1,0,0,1,1,1, /* UW[0:7] */
+ 0,0,0,0,0,0,0,0, /* Voice1[0:7] */
+ 0,0,0,0,0,0,0,0, /* Voice1[8:15] */
+ 0,0,0,0,0,0,0,0, /* Voice1[16:23] */
+ 0,0,0,0,0,0,0,0, /* Voice1[24:28] Voice2[0:3] */
+ 0,0,0,0,0,0,0,0, /* Voice2[4:11] */
+ 0,0,0,0,0,0,0,0, /* Voice2[12:19] */
+ 0,0,0,0,0,0,0,0};/* Voice2[20:28] */
+
+/* States */
+#define ST_NOSYNC 0 /* Not synchronized */
+#define ST_SYNC 1 /* Synchronized */
+
+/* Get a single bit out of an MSB-first packed byte array */
+#define UNPACK_BIT_MSBFIRST(bytes,bitidx) ((bytes)[(bitidx)>>3]>>(7-((bitidx)&0x7)))&0x1
+
+enum frame_payload_type {
+ FRAME_PAYLOAD_TYPE_VOICE,
+ FRAME_PAYLOAD_TYPE_DATA,
+};
+
+/* Place codec and other bits into a frame */
+void fvhff_frame_bits( int frame_type,
+ uint8_t bits_out[],
+ uint8_t codec2_in[],
+ uint8_t proto_in[],
+ uint8_t vc_in[]){
+ int i,ibit;
+ if(frame_type == FREEDV_VHF_FRAME_A){
+ /* Fill out frame with blank frame prototype */
+ for(i=0; i<96; i++)
+ bits_out[i] = A_blank[i];
+
+ /* Fill in protocol bits, if present */
+ if(proto_in!=NULL){
+ ibit = 0;
+ /* First half of protocol bits */
+ /* Extract and place in frame, MSB first */
+ for(i=4 ; i<16; i++){
+ bits_out[i] = UNPACK_BIT_MSBFIRST(proto_in,ibit);
+ ibit++;
+ }
+ /* Last set of protocol bits */
+ for(i=84; i<92; i++){
+ bits_out[i] = UNPACK_BIT_MSBFIRST(proto_in,ibit);
+ ibit++;
+ }
+ }
+
+ /* Fill in varicode bits, if present */
+ if(vc_in!=NULL){
+ bits_out[90] = vc_in[0];
+ bits_out[91] = vc_in[1];
+ }
+
+ /* Fill in codec2 bits, present or not */
+ ibit = 0;
+ for(i=16; i<40; i++){ /* First half */
+ bits_out[i] = UNPACK_BIT_MSBFIRST(codec2_in,ibit);
+ ibit++;
+ }
+ for(i=56; i<84; i++){ /* Second half */
+ bits_out[i] = UNPACK_BIT_MSBFIRST(codec2_in,ibit);
+ ibit++;
+ }
+ }else if(frame_type == FREEDV_HF_FRAME_B){
+ /* Pointers to both c2 frames so the bit unpack macro works */
+ uint8_t * codec2_in1 = &codec2_in[0];
+ uint8_t * codec2_in2 = &codec2_in[4];
+ /* Fill out frame with blank prototype */
+ for(i=0; i<64; i++)
+ bits_out[i] = B_blank[i];
+
+ /* Fill out first codec2 block */
+ ibit=0;
+ for(i=8; i<36; i++){
+ bits_out[i] = UNPACK_BIT_MSBFIRST(codec2_in1,ibit);
+ ibit++;
+ }
+ /* Fill out second codec2 block */
+ ibit=0;
+ for(i=36; i<64; i++){
+ bits_out[i] = UNPACK_BIT_MSBFIRST(codec2_in2,ibit);
+ ibit++;
+ }
+ }else if(frame_type == FREEDV_VHF_FRAME_AT){
+ /* Fill out frame with blank frame prototype */
+ for(i=0; i<88; i++)
+ bits_out[i] = AT_blank[i];
+
+ /* Fill in protocol bits, if present */
+ if(proto_in!=NULL){
+ ibit = 0;
+ /* First half of protocol bits */
+ /* Extract and place in frame, MSB first */
+ for(i=0 ; i<12; i++){
+ bits_out[i] = UNPACK_BIT_MSBFIRST(proto_in,ibit);
+ ibit++;
+ }
+ /* Last set of protocol bits */
+ for(i=80; i<88; i++){
+ bits_out[i] = UNPACK_BIT_MSBFIRST(proto_in,ibit);
+ ibit++;
+ }
+ }
+
+ /* Fill in varicode bits, if present */
+ if(vc_in!=NULL){
+ bits_out[86] = vc_in[0];
+ bits_out[87] = vc_in[1];
+ }
+
+ /* Fill in codec2 bits, present or not */
+ ibit = 0;
+ for(i=12; i<36; i++){ /* First half */
+ bits_out[i] = UNPACK_BIT_MSBFIRST(codec2_in,ibit);
+ ibit++;
+ }
+ for(i=52; i<80; i++){ /* Second half */
+ bits_out[i] = UNPACK_BIT_MSBFIRST(codec2_in,ibit);
+ ibit++;
+ }
+ }
+}
+
+/* Place data and other bits into a frame */
+void fvhff_frame_data_bits(struct freedv_vhf_deframer * def, int frame_type,
+ uint8_t bits_out[]){
+ int i,ibit;
+ if(frame_type == FREEDV_VHF_FRAME_A){
+ uint8_t data[8];
+ int end_bits;
+ int from_bit;
+ int bcast_bit;
+ int crc_bit;
+
+ /* Fill out frame with blank frame prototype */
+ for(i=0; i<4; i++)
+ bits_out[i] = A_blank[i];
+ for(i=92; i<96; i++)
+ bits_out[i] = A_blank[i];
+
+ /* UW data */
+ for (i=0; i < 16; i++)
+ bits_out[40 + i] = A_uw_d[i];
+
+ if (def->fdc)
+ freedv_data_channel_tx_frame(def->fdc, data, 8, &from_bit, &bcast_bit, &crc_bit, &end_bits);
+ else
+ return;
+
+ bits_out[4] = from_bit;
+ bits_out[5] = bcast_bit;
+ bits_out[6] = 0; /* unused */
+ bits_out[7] = 0; /* unused */
+
+ /* Fill in data bits */
+ ibit = 0;
+ for(i=8; i<40; i++){ /* First half */
+ bits_out[i] = UNPACK_BIT_MSBFIRST(data,ibit);
+ ibit++;
+ }
+ for(i=56; i<88; i++){ /* Second half */
+ bits_out[i] = UNPACK_BIT_MSBFIRST(data,ibit);
+ ibit++;
+ }
+
+ for (i = 0; i < 4; i++)
+ bits_out[88 + i] = (end_bits >> (3-i)) & 0x1;
+ } else if (frame_type == FREEDV_HF_FRAME_B){
+ uint8_t data[6];
+ int end_bits;
+ int from_bit;
+ int bcast_bit;
+ int crc_bit;
+
+ /* Fill out frame with blank prototype */
+ for(i=0; i<64; i++)
+ bits_out[i] = B_blank[i];
+
+ /* UW data */
+ for (i=0; i < 8; i++)
+ bits_out[0 + i] = B_uw_d[i];
+
+ if (def->fdc)
+ freedv_data_channel_tx_frame(def->fdc, data, 6, &from_bit, &bcast_bit, &crc_bit, &end_bits);
+ else
+ return;
+
+ bits_out[56] = from_bit;
+ bits_out[57] = bcast_bit;
+ bits_out[58] = crc_bit;
+ bits_out[59] = 0; /* unused */
+
+ /* Fill in data bits */
+ ibit = 0;
+ for(i=8; i<56; i++){ /* First half */
+ bits_out[i] = UNPACK_BIT_MSBFIRST(data,ibit);
+ ibit++;
+ }
+ for (i = 0; i < 4; i++)
+ bits_out[60 + i] = (end_bits >> (3-i)) & 0x1;
+ }
+}
+
+/* Init and allocate memory for a freedv-vhf framer/deframer */
+struct freedv_vhf_deframer * fvhff_create_deframer(uint8_t frame_type, int enable_bit_flip){
+ struct freedv_vhf_deframer * deframer;
+ uint8_t *bits,*invbits;
+ int frame_size;
+ int uw_size;
+
+ assert( (frame_type == FREEDV_VHF_FRAME_A) || (frame_type == FREEDV_HF_FRAME_B) );
+
+ /* It's a Type A frame */
+ if(frame_type == FREEDV_VHF_FRAME_A){
+ frame_size = 96;
+ uw_size = 16;
+ }else if(frame_type == FREEDV_HF_FRAME_B){
+ frame_size = 64;
+ uw_size = 8;
+ }else{
+ return NULL;
+ }
+
+ /* Allocate memory for the thing */
+ deframer = malloc(sizeof(struct freedv_vhf_deframer));
+ if(deframer == NULL)
+ return NULL;
+
+ /* Allocate the not-bit buffer */
+ if(enable_bit_flip){
+ invbits = malloc(sizeof(uint8_t)*frame_size);
+ if(invbits == NULL) {
+ free(deframer);
+ return NULL;
+ }
+ }else{
+ invbits = NULL;
+ }
+
+ /* Allocate the bit buffer */
+ bits = malloc(sizeof(uint8_t)*frame_size);
+ if(bits == NULL) {
+ free(deframer);
+ return NULL;
+ }
+
+ deframer->bits = bits;
+ deframer->invbits = invbits;
+ deframer->ftype = frame_type;
+ deframer->state = ST_NOSYNC;
+ deframer->bitptr = 0;
+ deframer->last_uw = 0;
+ deframer->miss_cnt = 0;
+ deframer->frame_size = frame_size;
+ deframer->uw_size = uw_size;
+ deframer->on_inv_bits = 0;
+ deframer->sym_size = 1;
+
+ deframer->ber_est = 0;
+ deframer->total_uw_bits = 0;
+ deframer->total_uw_err = 0;
+
+ deframer->fdc = NULL;
+
+ return deframer;
+}
+
+/* Get size of frame in bits */
+int fvhff_get_frame_size(struct freedv_vhf_deframer * def){
+ return def->frame_size;
+}
+
+/* Codec2 size in bytes */
+int fvhff_get_codec2_size(struct freedv_vhf_deframer * def){
+ if(def->ftype == FREEDV_VHF_FRAME_A){
+ return 7;
+ } else if(def->ftype == FREEDV_HF_FRAME_B){
+ return 8;
+ } else{
+ return 0;
+ }
+}
+
+/* Protocol bits in bits */
+int fvhff_get_proto_size(struct freedv_vhf_deframer * def){
+ if(def->ftype == FREEDV_VHF_FRAME_A){
+ return 20;
+ } else if(def->ftype == FREEDV_HF_FRAME_B){
+ return 0;
+ } else{
+ return 0;
+ }
+}
+
+/* Varicode bits in bits */
+int fvhff_get_varicode_size(struct freedv_vhf_deframer * def){
+ if(def->ftype == FREEDV_VHF_FRAME_A){
+ return 2;
+ } else if(def->ftype == FREEDV_HF_FRAME_B){
+ return 0;
+ } else{
+ return 0;
+ }
+}
+
+void fvhff_destroy_deframer(struct freedv_vhf_deframer * def){
+ freedv_data_channel_destroy(def->fdc);
+ free(def->bits);
+ free(def);
+}
+
+int fvhff_synchronized(struct freedv_vhf_deframer * def){
+ return (def->state) == ST_SYNC;
+}
+
+/* Search for a complete UW in a buffer of bits */
+size_t fvhff_search_uw(const uint8_t bits[],size_t nbits,
+ const uint8_t uw[], size_t uw_len,
+ size_t * delta_out, size_t bits_per_sym){
+
+ size_t ibits,iuw;
+ size_t delta_min = uw_len;
+ size_t delta;
+ size_t offset_min = 0;
+ /* Walk through buffer bits */
+ for(ibits = 0; ibits < nbits-uw_len; ibits+=bits_per_sym){
+ delta = 0;
+ for(iuw = 0; iuw < uw_len; iuw++){
+ if(bits[ibits+iuw] != uw[iuw]) delta++;
+ }
+ if( delta < delta_min ){
+ delta_min = delta;
+ offset_min = ibits;
+ }
+ }
+ if(delta_out != NULL) *delta_out = delta_min;
+ return offset_min;
+}
+
+/* See if the UW is where it should be, to within a tolerance, in a bit buffer */
+static int fvhff_match_uw(struct freedv_vhf_deframer * def,uint8_t bits[],int tol,int *rdiff, enum frame_payload_type *pt){
+ int frame_type = def->ftype;
+ int bitptr = def->bitptr;
+ int frame_size = def->frame_size;
+ int uw_len = def->uw_size;
+ int iuw,ibit;
+ const uint8_t * uw[2];
+ int uw_offset;
+ int diff[2] = { 0, 0 };
+ int i;
+ int match[2];
+ int r;
+
+ /* defaults to make compiler happy on -O3 */
+
+ *pt = FRAME_PAYLOAD_TYPE_VOICE;
+ *rdiff = 0;
+
+ /* Set up parameters for the standard type of frame */
+ if(frame_type == FREEDV_VHF_FRAME_A){
+ uw[0] = A_uw_v;
+ uw[1] = A_uw_d;
+ uw_len = 16;
+ uw_offset = 40;
+ } else if(frame_type == FREEDV_HF_FRAME_B){
+ uw[0] = B_uw_v;
+ uw[1] = B_uw_d;
+ uw_len = 8;
+ uw_offset = 0;
+ } else {
+ return 0;
+ }
+
+ /* Check both the voice and data UWs */
+ for (i = 0; i < 2; i++) {
+ /* Start bit pointer where UW should be */
+ ibit = bitptr + uw_offset;
+ if(ibit >= frame_size) ibit -= frame_size;
+ /* Walk through and match bits in frame with bits of UW */
+ for(iuw=0; iuw<uw_len; iuw++){
+ if(bits[ibit] != uw[i][iuw]) diff[i]++;
+ ibit++;
+ if(ibit >= frame_size) ibit = 0;
+ }
+ match[i] = diff[i] <= tol;
+ //fprintf(stderr, "diff[%d]: %d tol: %d\n", i, diff[i], tol);
+ }
+ /* Pick the best matching UW */
+
+ if (diff[0] < diff[1]) {
+ r = match[0];
+ *rdiff = diff[0];
+ *pt = FRAME_PAYLOAD_TYPE_VOICE;
+ } else {
+ r = match[1];
+ *rdiff = diff[1];
+ *pt = FRAME_PAYLOAD_TYPE_DATA;
+ }
+
+ return r;
+}
+
+static void fvhff_extract_frame_voice(struct freedv_vhf_deframer * def,uint8_t bits[],
+ uint8_t codec2_out[],uint8_t proto_out[],uint8_t vc_out[]){
+ int frame_type = def->ftype;
+ int bitptr = def->bitptr;
+ int frame_size = def->frame_size;
+ int iframe,ibit;
+
+ if(frame_type == FREEDV_VHF_FRAME_A){
+ /* Extract codec2 bits */
+ memset(codec2_out,0,7);
+ ibit = 0;
+ /* Extract and pack first half, MSB first */
+ iframe = bitptr+16;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<24;ibit++){
+ codec2_out[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+
+ /* Extract and pack last half, MSB first */
+ iframe = bitptr+56;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<52;ibit++){
+ codec2_out[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+ /* Extract varicode bits, if wanted */
+ if(vc_out!=NULL){
+ iframe = bitptr+90;
+ if(iframe >= frame_size) iframe-=frame_size;
+ vc_out[0] = bits[iframe];
+ iframe++;
+ vc_out[1] = bits[iframe];
+ }
+ /* Extract protocol bits, if proto is passed through */
+ if(proto_out!=NULL){
+ /* Clear protocol bit array */
+ memset(proto_out,0,3);
+ ibit = 0;
+ /* Extract and pack first half, MSB first */
+ iframe = bitptr+4;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<12;ibit++){
+ proto_out[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+
+ /* Extract and pack last half, MSB first */
+ iframe = bitptr+84;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<20;ibit++){
+ proto_out[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+ }
+
+ }else if(frame_type == FREEDV_HF_FRAME_B){
+ /* Pointers to both c2 frames */
+ uint8_t * codec2_out1 = &codec2_out[0];
+ uint8_t * codec2_out2 = &codec2_out[4];
+
+ /* Extract codec2 bits */
+ memset(codec2_out,0,8);
+ ibit = 0;
+
+ /* Extract and pack first c2 frame, MSB first */
+ iframe = bitptr+8;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<28;ibit++){
+ codec2_out1[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+
+ /* Extract and pack second c2 frame, MSB first */
+ iframe = bitptr+36;
+ ibit = 0;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<28;ibit++){
+ codec2_out2[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+ }else if(frame_type == FREEDV_VHF_FRAME_AT){
+ /* Extract codec2 bits */
+ memset(codec2_out,0,7);
+ ibit = 0;
+ /* Extract and pack first half, MSB first */
+ iframe = bitptr+12;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<24;ibit++){
+ codec2_out[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+
+ /* Extract and pack last half, MSB first */
+ iframe = bitptr+52;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<52;ibit++){
+ codec2_out[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+ /* Extract varicode bits, if wanted */
+ if(vc_out!=NULL){
+ iframe = bitptr+86;
+ if(iframe >= frame_size) iframe-=frame_size;
+ vc_out[0] = bits[iframe];
+ iframe++;
+ vc_out[1] = bits[iframe];
+ }
+ /* Extract protocol bits, if proto is passed through */
+ if(proto_out!=NULL){
+ /* Clear protocol bit array */
+ memset(proto_out,0,3);
+ ibit = 0;
+ /* Extract and pack first half, MSB first */
+ iframe = bitptr+4;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<12;ibit++){
+ proto_out[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+
+ /* Extract and pack last half, MSB first */
+ iframe = bitptr+84;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<20;ibit++){
+ proto_out[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+ }
+
+ }
+}
+
+static void fvhff_extract_frame_data(struct freedv_vhf_deframer * def,uint8_t bits[]){
+ int frame_type = def->ftype;
+ int bitptr = def->bitptr;
+ int frame_size = def->frame_size;
+ int iframe,ibit;
+
+ if(frame_type == FREEDV_VHF_FRAME_A){
+ uint8_t data[8];
+ int end_bits = 0;
+ int from_bit;
+ int bcast_bit;
+
+ iframe = bitptr+4;
+ if(iframe >= frame_size) iframe-=frame_size;
+ from_bit = bits[iframe];
+ iframe++;
+ if(iframe >= frame_size) iframe-=frame_size;
+ bcast_bit = bits[iframe];
+
+ /* Extract data bits */
+ memset(data,0,8);
+ ibit = 0;
+ /* Extract and pack first half, MSB first */
+ iframe = bitptr+8;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<32;ibit++){
+ data[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+
+ /* Extract and pack last half, MSB first */
+ iframe = bitptr+56;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<64;ibit++){
+ data[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+
+ /* Extract endbits value, MSB first*/
+ iframe = bitptr+88;
+ ibit = 0;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<4;ibit++){
+ end_bits |= (bits[iframe]&0x1)<<(3-(ibit));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+
+ if (def->fdc) {
+ freedv_data_channel_rx_frame(def->fdc, data, 8, from_bit, bcast_bit, 0, end_bits);
+ }
+ } else if(frame_type == FREEDV_HF_FRAME_B){
+ uint8_t data[6];
+ int end_bits = 0;
+ int from_bit;
+ int bcast_bit;
+ int crc_bit;
+
+ ibit = 0;
+ memset(data,0,6);
+
+ /* Extract and pack first c2 frame, MSB first */
+ iframe = bitptr+8;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<48;ibit++){
+ data[ibit>>3] |= (bits[iframe]&0x1)<<(7-(ibit&0x7));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+
+ iframe = bitptr+56;
+ if(iframe >= frame_size) iframe-=frame_size;
+ from_bit = bits[iframe];
+ iframe++;
+ if(iframe >= frame_size) iframe-=frame_size;
+ bcast_bit = bits[iframe];
+ iframe++;
+ if(iframe >= frame_size) iframe-=frame_size;
+ crc_bit = bits[iframe];
+
+ /* Extract endbits value, MSB first*/
+ iframe = bitptr+60;
+ ibit = 0;
+ if(iframe >= frame_size) iframe-=frame_size;
+ for(;ibit<4;ibit++){
+ end_bits |= (bits[iframe]&0x1)<<(3-(ibit));
+ iframe++;
+ if(iframe >= frame_size) iframe=0;
+ }
+
+ if (def->fdc) {
+ freedv_data_channel_rx_frame(def->fdc, data, 6, from_bit, bcast_bit, crc_bit, end_bits);
+ }
+ }
+}
+
+static void fvhff_extract_frame(struct freedv_vhf_deframer * def,uint8_t bits[],uint8_t codec2_out[],
+ uint8_t proto_out[],uint8_t vc_out[],enum frame_payload_type pt){
+ switch (pt) {
+ case FRAME_PAYLOAD_TYPE_VOICE:
+ fvhff_extract_frame_voice(def, bits, codec2_out, proto_out, vc_out);
+ break;
+ case FRAME_PAYLOAD_TYPE_DATA:
+ fvhff_extract_frame_data(def, bits);
+ break;
+ }
+}
+
+/*
+ * Try to find the UW and extract codec/proto/vc bits in def->frame_size bits
+ */
+int fvhff_deframe_bits(struct freedv_vhf_deframer * def,uint8_t codec2_out[],uint8_t proto_out[],
+ uint8_t vc_out[],uint8_t bits_in[]){
+ uint8_t * strbits = def->bits;
+ uint8_t * invbits = def->invbits;
+ uint8_t * bits;
+ int on_inv_bits = def->on_inv_bits;
+ int frame_type = def->ftype;
+ int state = def->state;
+ int bitptr = def->bitptr;
+ int last_uw = def->last_uw;
+ int miss_cnt = def->miss_cnt;
+ int frame_size = def->frame_size;
+ int uw_size = def->uw_size;
+ int uw_diff;
+ int i;
+ int uw_first_tol;
+ int uw_sync_tol;
+ int miss_tol;
+ int extracted_frame = 0;
+ enum frame_payload_type pt = FRAME_PAYLOAD_TYPE_VOICE;
+
+ /* Possibly set up frame-specific params here */
+ if(frame_type == FREEDV_VHF_FRAME_A){
+ uw_first_tol = 1; /* The UW bit-error tolerance for the first frame */
+ uw_sync_tol = 3; /* The UW bit error tolerance for frames after sync */
+ miss_tol = 4; /* How many UWs may be missed before going into the de-synced state */
+ }else if(frame_type == FREEDV_HF_FRAME_B){
+ uw_first_tol = 0; /* The UW bit-error tolerance for the first frame */
+ uw_sync_tol = 1; /* The UW bit error tolerance for frames after sync */
+ miss_tol = 3; /* How many UWs may be missed before going into the de-synced state */
+ }else{
+ return 0;
+ }
+
+ /* Skip N bits for multi-bit symbol modems */
+ for(i=0; i<frame_size; i++){
+ /* Put a bit in the buffer */
+ strbits[bitptr] = bits_in[i];
+ /* If we're checking the inverted bitstream, put a bit in it */
+ if(invbits!=NULL)
+ invbits[bitptr] = bits_in[i]?0:1;
+
+ bitptr++;
+ if(bitptr >= frame_size) bitptr -= frame_size;
+ def->bitptr = bitptr;
+ /* Enter state machine */
+ if(state==ST_SYNC){
+ /* Already synchronized, just wait till UW is back where it should be */
+ last_uw++;
+ if(invbits!=NULL){
+ if(on_inv_bits)
+ bits = invbits;
+ else
+ bits = strbits;
+ }else{
+ bits=strbits;
+ }
+ /* UW should be here. We're sunk, so deframe anyway */
+ if(last_uw == frame_size){
+ last_uw = 0;
+
+ if(!fvhff_match_uw(def,bits,uw_sync_tol,&uw_diff, &pt))
+ miss_cnt++;
+ else
+ miss_cnt=0;
+
+ /* If we go over the miss tolerance, go into no-sync */
+ if(miss_cnt>miss_tol){
+ state = ST_NOSYNC;
+ }
+ /* Extract the bits */
+ extracted_frame = 1;
+ fvhff_extract_frame(def,bits,codec2_out,proto_out,vc_out,pt);
+
+ /* Update BER estimate */
+ def->ber_est = (.995*def->ber_est) + (.005*((float)uw_diff)/((float)uw_size));
+ def->total_uw_bits += uw_size;
+ def->total_uw_err += uw_diff;
+ }
+ /* Not yet sunk */
+ }else{
+ /* It's a sync!*/
+ if(invbits!=NULL){
+ if(fvhff_match_uw(def,invbits,uw_first_tol, &uw_diff, &pt)){
+ state = ST_SYNC;
+ last_uw = 0;
+ miss_cnt = 0;
+ extracted_frame = 1;
+ on_inv_bits = 1;
+ fvhff_extract_frame(def,invbits,codec2_out,proto_out,vc_out,pt);
+ /* Update BER estimate */
+ def->ber_est = (.995*def->ber_est) + (.005*((float)uw_diff)/((float)uw_size));
+ def->total_uw_bits += uw_size;
+ def->total_uw_err += uw_diff;
+ }
+ }
+ if(fvhff_match_uw(def,strbits,uw_first_tol, &uw_diff, &pt)){
+ state = ST_SYNC;
+ last_uw = 0;
+ miss_cnt = 0;
+ extracted_frame = 1;
+ on_inv_bits = 0;
+ fvhff_extract_frame(def,strbits,codec2_out,proto_out,vc_out,pt);
+ /* Update BER estimate */
+ def->ber_est = (.995*def->ber_est) + (.005*((float)uw_diff)/((float)uw_size));
+ def->total_uw_bits += uw_size;
+ def->total_uw_err += uw_diff;
+ }
+ }
+ }
+ def->state = state;
+ def->last_uw = last_uw;
+ def->miss_cnt = miss_cnt;
+ def->on_inv_bits = on_inv_bits;
+ /* return sync state and presence of extracted voice bits.
+ only sync for data frames, they are already handled by callback */
+ return (extracted_frame ? FREEDV_RX_SYNC : 0) | (pt == FRAME_PAYLOAD_TYPE_VOICE ? FREEDV_RX_BITS : 0);
+}
generated by cgit v1.2.3 (git 2.46.0) at 2026-01-26 23:44:52 +0000